Problem: A goblet contains $6$ red marbles, $9$ green marbles, and $11$ blue marbles. If a marble is randomly chosen, what is the probability that it is red?
Answer: There are $6 + 9 + 11 = 26$ marbles in the goblet. There are $6$ red marbles. The probability is $ \frac{6}{26} = \dfrac{3}{13}$.